feat: Add site_path method to GlobalArgs

src/bin/cli/mod.rs

@@ -1,11 +1,36 @@
 use clap::{Args, Parser, Subcommand};
 use color_eyre::eyre::Result;
-use std::path::PathBuf;
+use snafu::{ensure, ResultExt, Snafu};
+use std::{env::current_dir, path::PathBuf};
 
 mod init;
 
 pub use init::InitArgs;
 
+/// Error encountered while parsing CLI
+#[derive(Debug, Snafu)]
+pub enum CliError {
+    /// Site path is not a directory
+    #[snafu(display("Path exists, but is not a directory: {:?}", path))]
+    NotADirectory {
+        /// The nonexistant path
+        path: PathBuf,
+    },
+    /// Failed checking to see if a path exists
+    #[snafu(display("Failed checking for existance of path: {:?}", path))]
+    ExistanceCheck {
+        /// The nonexistant path
+        path: PathBuf,
+        /// The underlying error
+        source: std::io::Error,
+    },
+    /// Failed getting the current directory
+    CurrentDirectory {
+        /// The underlying error
+        source: std::io::Error,
+    },
+}
+
 /// Djot based static site generator
 #[derive(Parser, Debug)]
 #[command(author, version, about, long_about=None)]
@@ -27,6 +52,30 @@ pub struct GlobalArgs {
     pub site_path: Option<PathBuf>,
 }
 
+impl GlobalArgs {
+    /// Get the site path folder
+    ///
+    /// Defaults to the current working directory
+    pub fn site_path(&self) -> Result<PathBuf, CliError> {
+        if let Some(site_path) = self.site_path.as_ref() {
+            // If the path exists, make sure it is a directory
+            if site_path
+                .try_exists()
+                .context(ExistanceCheckSnafu { path: site_path })?
+            {
+                ensure!(site_path.is_dir(), NotADirectorySnafu { path: site_path });
+                Ok(site_path.clone())
+            } else {
+                // It doesn't exist yet, so go ahead and return
+                Ok(site_path.clone())
+            }
+        } else {
+            let current_dir = current_dir().context(CurrentDirectorySnafu)?;
+            Ok(current_dir)
+        }
+    }
+}
+
 /// Command to run
 #[derive(Subcommand, Debug)]
 pub enum Command {